The PRINTING United Alliance Glossary serves as an excellent industry terminology resource. It is the language by which we all communicate. Without it, universal understanding would be impossible.

To keep our constituents well informed about changes to the increasingly complex industry terminology, PRINTING United Alliance has developed this glossary of terms. Definitions are for general reference only. Usage may vary between companies, individuals, or national and country customs. The information presented is as accurate as the authors and editors can ascertain and PRINTING United Alliance assumes no responsibility for the use of information presented herein.
  • Skinning
    A thin layer of dried ink that forms on top of a stored ink.
  • SKU
    Retail inventory term for stock-keeping unit.
  • Slide
    A 35 mm transparency.
  • Slide arm machine
    The heating element of a heat transfer machine that slides away from the lower platen.
  • Sliding latch lock
    A lock used for set-up of folded display parts.
  • Slip
    A slurry containing clay minerals.
  • Slip coating
    A ceramic material or mixture other than glaze that is applied to a ceramic body and fired.
  • Slip sheet
    Inexpensive sheet of waxed or treated paper placed between finished decals to prevent them from adhering to one another during shipment.
  • Slipping
    A defect that occurs during firing where the decoration slides from its original printed position down the side of the ware.
  • Slit
    (1) To cut paper using a disk or wheel; (2) To cut through the backing sheet or release liner of a decal to facilitate removal; (3) A cut through any sheet material for any purpose to indicate a separation line or to permit the escape of air if the sheet is closely contacted with another true surface.
  • Slitter
    A web cutting device that is mounted on a rewinder or other machine for cutting large parent rolls into narrower widths.
  • Slitting
    The reduction of a sheet or roll material by making parallel cuts along one dimension in order to form sheets or strips with less width.
  • Sliver
    A loose, untwisted strand of fibers that is removed after carding of fabric.
  • Slow scan direction
    The raster direction along which successive lines of pixels are arrayed perpendicular to the fast scan direction.
  • Slug
    (1) A strip of metal usually 6 point used for spacing in type composition; (2) One solid piece of line type.
  • Slur
    (1) A blur or smear in a print caused by movement at the moment of printing; (2) Undesirable phenomenon of halftone dots becoming slightly elongated during printing.
  • Slurry
    A concentration of solid particles and rheological modifiers in water.
  • Slush molding
    A method for casting thermoplastic where the resin in liquid form is poured into a hot mold where a viscous skin forms.
  • SM
    Acceptable acronym for surface mount.
  • Small quantity generator (SQG)
    in the US a firm that produces less than 100 kg (2200 lbs) of hazardous waste in a calendar month.
  • Smearing
    The overspreading of ink into non image area.
  • Smelt
    To melt or fuse.
    Acceptable acronym for solder mask over bare copper.
  • Smoothness
    Flatness of a surface free from projections or irregularities of the surface; to make flat or even.
  • Smudge resistance
    The ability of a freshly printed surface to resist ink blurring or smearing.